A heat exchanger is a device used to passively transfer heat from one material to another. These materials may be liquid or gaseous, depending on the situation in which the heat exchanger is being utilized. Heat exchangers are basically two chambers separated by a heat transmitting barrier
Typical refrigerant-to-water heat exchangers, are available as coaxial heat exchangers or brazed plate heat exchangers. Coaxial heat exchangers consist of a double-walled corrugated copper tube inserted through a larger steel tube. Heat exchange takes place as water flows through the center of the corrugated copper tube and a refrigerant flows between the corrugated copper and steel tubes. A double-walled coaxial heat exchanger, using corrugated copper, typically requires a 0.060-0.080 inch wall thickness of the corrugated copper tube. There is therefore a need for a double-walled heat exchanger with thinner walls.